Material Properties of Spinal Motion Segments - The material properties of human spinal motion segments under quasistatic physiological (complex) loading was found. The effects of high strain rate loading on the cervical motion segments was studied for axial compression, pure lateral bending, AP extension and flexion, torsion and direct shear loadings. The torsional behavior of the thoracolumbar transition vertebrae, i.e., T12/L1 intervertebral joint, was singled out for detail analysis and study. Frontal Head Impact - Using a Remington Humane Stunner as an impactor, the observable neuropathological lesions were correlated with the mechanical parameters of impact. The neurohistologic processing is in progress. Finite-Element Model Closed-Head and Neck Injuries - A finite-element computer model to stimulate closed-head and neck injury is nearing completion. This model is distinguished from others by the inclusion of morphologically "exact" skull, dura mater, falx cerebri, tentorium, CSF, cerebrum, brainstem, spinal cord as well as the neck neuromusculature. This is, by far, the most comprehensive computer model for the study of closed-head injury. Optimization of Viscoeleastic Elastic Motion Segment Data - A previous scheme for the identification of the elastic material properties of the intervertebral joint was extended to include the determination of the viscoelastic parameters from creep and/or relaxation tests.